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Tips & Tricks
Ask about and post about tips and tricks you use while modelling.
Glueing to paint
Rudiix
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Victoria, Australia
Member Since: August 19, 2020
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Posted: Tuesday, August 18, 2020 - 10:42 PM UTC
Hi, i am a newbie who is building a billings smitt rotterdam. It is a wood boat but needs to be painted.
The instruction say to paint many bits before assembly. I have painted the hull and need to glue rails and other detail things on it. It would be very difficult to scrape the paint of successfully for some items such as rails prior to glueing.
Does anyone have any tips on glueing to painted surfaces. Roughing up is not an option in some cases.
Namabiiru
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MODEL SHIPWRIGHTS
#399
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Posted: Tuesday, August 18, 2020 - 11:10 PM UTC
Rudy,
As a general rule, trying to glue to paint is not a good idea. IF you have a good primer coat and IF the piece is not going to get stressed (bumped, pulled, etc.) then you might get away with it, but I would say normally it's worth trying to remove the paint from the contact surface first. Depending on how skillful you are at applying glue, there's a good chance the paint is going to need to be touched up afterward anyway.

There is also the option of assembling, masking and then painting, but it is difficult to recommend that without knowing more of the specifics of what is being glued on to the hull.

Good luck! Send pics of the results!

Scarred
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Posted: Wednesday, August 19, 2020 - 07:14 AM UTC
I've used cyanoacrylate, aka CA or superglue, to glue painted parts together. Epoxy glues will also work. But and I mean BUT you need to test them on scraps painted with the same paints on the same material that the kit is made from.

Also let the paints fully dry and cure before gluing. This can take several days.

And remember that the joint between painted parts is weaker than the joint between non painted parts. The weakness is the paint/plastic bond, or in your case the paint/wood bond. If the parts separate you will most likely see that the paint has lifted from one of the parts.

When I have to paint parts before gluing them together and I can't scrape away the paint after glueing I will put a tiny piece of tape on the gluing surfaces which I remove after the paint dries. Another thing I'll do is pre fit the part before painting and put a tiny bit of PVA glue (elmers glue) on the part position the part like I'm gluing it in place then remove it and let the glue dry. This will leave a bit of glue on the gluing surfaces that will mask it from the paint. After painting I'll use a dental pick, knife point or sewing needle to carefully remove the dry glue. I've done this on plastic, photo etch and resin but never on wood. PVA works great gluing wood together so I don't think it will work.
barkingdigger
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ARMORAMA
#013
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Posted: Thursday, August 20, 2020 - 01:32 AM UTC
Are the details a different material to the hull? If gluing metal rails to a wooden hull then it is best to make a mechanical connection such as a pin that extends into the wood, giving strength to the joint. It's easy for large parts - just drill holes in the part and the hull to accept short lengths of brass rod. But for narrow items like the feet of railings it can be tricky.
RobinNilsson
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Posted: Thursday, August 20, 2020 - 08:33 AM UTC
The wood in that kit is mostly abachi which is soft and lets go of fibers so glueing to paint is marginally less effective compared to gluing to the wood.
Wood on wood works but not for the brass pieces.
Kevlar06
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Posted: Thursday, August 20, 2020 - 09:12 AM UTC
As Robin indicates, wooden shipbuilding usually requires “wood on wood” with a good adhesive (my favorite is Uhu). Many Billings kits use a fibrous balsa like material, which absorbs enamel and lacquer paints, causing the mated parts to pull the painted wood apart at a glue joint, exposing a ragged hole in the wood surface. I like to “stain” my wood with a good water based colored stain, prior to painting, rather than using enamels, acrylics or lacquers. This allows me to use my favorite glue (again Uhu), join the parts, and when dry, I can paint over the join. Occasionally, I’ll attach a part with a good, two part 5 minute epoxy rated for wood. This is especially true when gluing different materials (such as metal, plastic, and wood). I seldom use CA glues on wood, as they are almost impossible to predict in their penetration qualities, and sometimes Have detrimental effects on wood grained surfaces. If you need to unavoidably join two painted wood surfaces, epoxy Is really you best bet.
VR, Russ
Rudiix
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Victoria, Australia
Member Since: August 19, 2020
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Posted: Thursday, August 20, 2020 - 11:14 AM UTC
HI,

Thanks for all the helpful advice. I opened up the bag with 245 Rails (Groan) and found them to be quite solid with a protrusion at the bottom for sticking into the wood. I got my scalpel and made a hole in the wood and pushed it in. It stayed there quite well and with a drop of epoxy should hold well.
Does anyone know where i can find online a build for the smitt rotterdam.

Again all thanks for all the great advice.
Rudiix
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Victoria, Australia
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Posted: Thursday, August 20, 2020 - 11:16 AM UTC
Thanks for the advise. I have used 5 minute epoxy throughout the build. A bit finicky at times but i find it holds very well.
Rudiix
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Victoria, Australia
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Posted: Thursday, August 20, 2020 - 11:18 AM UTC
Thanks, That's the impression i got.
Rudiix
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Victoria, Australia
Member Since: August 19, 2020
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Posted: Thursday, August 20, 2020 - 11:19 AM UTC
Thankyou, That's very creative and a great idea.